Capella, based in Atlanta, has been operating since 2002 and currently has three hotel brands: Capella Hotels & Resorts, Solis Hotels & Resorts and Auriga Spa.
The Kwee family already owns Singapore-based property development firm Pontiac Land Group which features several Singapore hotels in its portfolio.
Terms of the deal have not been disclosed and Schulze, who was one of the founders of the Ritz-Carlton Hotel Company in the 1980s, will remain on the Capella board as chairman emeritus with Nicholas Clayton becoming chief executive. Capella will also move its headquarters to Singapore.
Capella currently operates seven hotels including five Capella-branded properties in Dusseldorf, Ixtapa in Mexico, Shanghai, Singapore and Saint Lucia. Two new Capella resorts are due to open next year in Bali and Bangkok.
The group also runs two Solis-branded hotels including Lough Eske Castle in Donegal, Ireland, with new resorts in Bali, Guangzhou, Orlando and Atlanta under construction.